Power Steering History

Various technologies have been employed for power steering

Mechanical Power Steering

Originally power steering had a pump attached to the serpentine belt, this would then be connected to the steering rack through rigid hydraulic fluid lines. Many cars during this era would not ship with any form of power assisted steering which allowed manufacturers flexibility.

Volkswagen Golf MK3 Mechanically Driven Power Steering Pump

Electro Hydraulic Power Steering

With looming emissions standards and the desire to increase fuel efficiency the hydraulic pump was moved from being belt driven through the engine to being an electric pump, these typically lived behind the bumper on the left, these systems allowed for variable support assistance and full diagnostic capabilities, they however are unable to take external steering commands.

Skoda Fabia MK1 Electro Hydraulic Power Steering Pump

Electro Mechanical Power Steering

In a further effort to streamline cars the newest generation of electro mechanical power steering was introduced, on the PQ25 platform these are implemented inside the steering column, this allows the module to be hidden behind the dashboard.

Polo 6C Column Mounted Electro Mechanical Power Steering Module